Evolution/Extinction/Evidence Flashcards
What are fossils?
solidified remains or imprints of once-living
What are constructed using fossils?
Fossil Record
What is a fossil record also known as?
The historical sequence of life
What are Paleontologists?
Scientist who look for fossils to help them reconstruct what happened in the past
What is the Earth’s crust arranged in?
Layers of rock and soil stacked on top of each other
Could fossils be any living organism?
Yes
The deeper the layer, the older or younger the fossil?
The older the fossil
What is the PA state fossil?
Trilobite
What are Vestigial Structures?
Remnants of structures that had a useful role at one time but no longer do
Why are there Vestigial Structures?
It suggests that the organism evolved from another life form where that structure played an important role.
What are examples of Vestigial Structures?
Wisdom Teeth, Human Tailbones, Hind-limb bones in whale and some snakes
What are Skeletal Structures?
Bone structures of mammals are very similar a common origin
What makes someone have similar DNA with another person?
When they are closely related.
What organisms have DNA?
ALL ORGANISMS!
How identical is a chimp’s gene and a human’s gene?
98%
How identical is a mouse’s gene and a human’s gene?
70%
What are the basic unit of life?
Cells
What do all living organisms start as?
A single cell
What is a geologic time scale?
An outline of history of life on Earth
What are large blocks of time divided called?
eras
What are eras characterized by?
The animal that dominated the Earth at that time.
How many percent of species that ever existed are now extinct?
99%
What are some natural causes of extinction?
Climate change, Pollution, Disease
What also happens during Extinction?
evolution of new species that usually quickly fill in the space another species’ extinction creates
What is background extinction?
The continual extinction of species (basically slowly dying)
What is mass extinction?
The accelerated extinction rates that sharply reduce the diversity of life on Earth (IMMEDIATE!!!)
What did continents used to be?
A single landmass called pangaea
Where are the organisms that evolved before the split may be represent on today?
On all present continents
Where are the organisms that evolved after the split may be represent on today?
Only found in certain places
